The object of the proposed research is to continue studies on the reactions of singlet oxygen with organic substrates, particularly those systems which are key components in biological systems. Particular attention will be given to enamines, enols, polycarbonyl systems, and to the second-stage effects of neighboring groups on the ene reaction. The research will involve model studies on the mechanism by which singlet oxygen may be transferred to acceptors in biochemical processes. Donor molecules to be studied will include 9,10-diphenylanthracene peroxide fused to a crown-ether binding site, capable of releasing molecular oxygen on thermolysis. Acceptors will incorporate a residue capable of complexing with the ether portion of the donor, and separated from the acceptor site by a carbon chain of suitable size. The acceptor substrates will consist of electron rich olefins, sulfides, and heterocyclic systems. Another oxygen transfer (donor) system will be derived from the incorporation, in a polymer network, of sulfide residues which can be converted to persulfoxides by reaction with singlet oxygen. The persulfoxides may then in a separate stage serve as donors of atomic oxygen to suitable acceptors such as olefins, sulfides, amines and electron-rich heterocyclic systems.